World Meteorological Organization

The World Meteorological Organization (WMO) is a specialised agency of the United Nations responsible for fostering international cooperation in the fields of atmospheric science, climatology, hydrology, and geophysics. Headquartered in Geneva, Switzerland, it serves as a vital hub for the free and unrestricted exchange of meteorological and hydrological information among its 193 members, which include both countries and territories. The WMO plays an essential role in global efforts to monitor weather, understand climate systems, improve forecasting capabilities, and address environmental challenges such as climate change and natural hazards.
The organisation traces its origins to the International Meteorological Organization (IMO), founded in 1873 as a non-governmental body to facilitate the exchange of weather data. The need for an intergovernmental framework led to major reforms, culminating in the World Meteorological Convention of 1947. The Convention entered into force on 23 March 1950, marking the birth of the WMO as a UN-related organisation. This date is commemorated annually as World Meteorological Day, which highlights key aspects of the organisation’s work and global meteorological initiatives.

Origins and Historical Development

The foundation of the WMO lies in the nineteenth-century scientific movement for systematic observation of weather and climate. The IMO provided the earliest platform for cooperation, but as meteorology became essential to aviation, agriculture, and international safety, a governmental structure became necessary. The World Meteorological Convention reorganised the IMO into the WMO, enabling formal agreements, standardisation of observations, and coordination of global research programmes.
The WMO formally joined the United Nations system in 1951. From the outset, it expanded the remit of its predecessor by integrating meteorology with hydrology and related geophysical sciences. As global environmental awareness grew, the organisation’s mandate broadened to include climate change, the monitoring of greenhouse gases, and disaster risk reduction.

Governance and organisational structure

The WMO operates under the Convention of the World Meteorological Organization, which outlines its purposes and institutional arrangements. Governance is anchored in three principal bodies:

• The World Meteorological Congress, the organisation’s supreme authority, meets every four years to determine policies, approve budgets, and set strategic priorities. Each member state and territory participates through a Permanent Representative.
• The Executive Council, elected by the Congress, ensures implementation of Congress decisions. It provides guidance on scientific and operational matters and is chaired by a President of the Organisation—currently Abdulla Al Mandous of the United Arab Emirates.
• The Secretariat, headed by a Secretary-General appointed by the Congress, manages daily operations. The Secretariat comprises eight departments and has a staff of around 200. As of 2024, Celeste Saulo serves as Secretary-General.

Globally, WMO’s work is structured through six regional associations that coordinate meteorological activities in Africa, Asia, South America, North America–Central America–Caribbean, South-West Pacific, and Europe. This regional system enhances collaboration on climate monitoring, capacity-building, forecasting, and the operation of observation networks.

Core Activities and Programmes

The WMO provides essential scientific coordination and operational frameworks to support meteorology and related sciences worldwide. Key areas of activity include:

• Disaster risk reduction: Strengthening early-warning systems to reduce loss of life and property from extreme weather events.
• The Global Framework for Climate Services (GFCS): Enhancing the availability and use of climate information in sectors such as agriculture, health, water, and disaster management.
• WMO Integrated Global Observing System (WIGOS): Unifying global atmospheric, oceanic, cryospheric, and terrestrial observations to support accurate forecasts and climate assessments.
• Aviation meteorology: Providing standards and data essential for safe and efficient international aviation operations.
• Polar and high-mountain initiatives: Improving monitoring and understanding of sensitive regions critical to global climate systems.
• Capacity development: Supporting developing countries in building institutional, technical, and human capabilities to operate meteorological and hydrological services.

The WMO also hosts major scientific and technical congresses, facilitates collaboration with research institutions, and works closely with UN partners on sustainable development, disaster resilience, and climate policy.

Meteorological Data Standards and Codes

In line with its mandate to promote standardised meteorological practices, the WMO maintains internationally recognised coding systems for data exchange. Traditional character-based codes include:

• SYNOP for surface weather observations
• CLIMAT for climate summaries
• TEMP for upper-air observations

To accommodate modern data demands, the organisation also administers more sophisticated codes such as BUFR, designed for portability and extensibility, and GRIB, widely used for gridded numerical weather prediction data.
The WMO recommends the use of the International System of Units (SI) for global meteorological observations. These include Celsius (or Kelvin) for temperature, metres per second for wind speed, hectopascals for atmospheric pressure, and millimetres for precipitation and evaporation. Clear and standardised measurement protocols ensure consistency across national services.

Publications and Public Outreach

To increase public understanding of climate and weather science, the WMO produces several major publications:

• WMO Bulletin (twice annually)
• WMO Greenhouse Gas Bulletin (annual)
• WMO Statement on the Status of the World Climate (annual)
• World Meteorological Organization at a Glance
• WMO for Youth

These reports provide updates on global temperatures, extreme weather patterns, climate indicators such as greenhouse gas concentrations and sea-level rise, and scientific advances in meteorology. The organisation also contributes to multi-institutional reports, including the United in Science series launched in 2020, which synthesises findings from leading climate research bodies.

Awards and Recognition

The WMO administers several international awards to recognise outstanding contributions to meteorology, climate science, and environmental services. These include:

• International Meteorological Organization Prize
• Professor Dr Vilho Väisälä Awards
• WMO Research Award for Young Scientists
• Professor Mariolopoulos Award

In 2007, the Intergovernmental Panel on Climate Change (IPCC), created jointly by the WMO and the United Nations Environment Programme, received the Nobel Peace Prize for its work on climate change science and communication.

Membership and Regional Structure

As of 2023, the WMO comprises 187 member states and 6 member territories. Most UN member states belong to the organisation, with exceptions including Equatorial Guinea, Grenada, Liechtenstein, the Marshall Islands, Palau, Saint Kitts and Nevis, Saint Vincent and the Grenadines, and San Marino. Several non-UN territories—such as the Cook Islands, Niue, French Polynesia, Hong Kong, and Macau—participate fully in WMO activities.
Members are organised into six regional associations, each responsible for coordinating meteorological activities in its region. For example:

• Regional Association I (Africa) covers 57 states.
• Regional Association II (Asia) includes 33 states and two territories.
• Regional Association III (South America) includes 13 states.

These associations ensure that WMO programmes are adapted to local needs and enhance cooperation among national meteorological and hydrological services.

Global Significance

The World Meteorological Organization plays an indispensable role in monitoring the Earth’s atmosphere, advancing climate science, and safeguarding societies against hazards such as storms, floods, droughts, and heatwaves. Its coordination of global observational networks and standardisation efforts underpin modern forecasting systems and climate research. As climate change accelerates, the WMO’s contributions are vital to scientific understanding, international policy formation, and the resilience of communities worldwide.